diff --git a/mypy.ini b/mypy.ini
index d8eb262f..9167447d 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -17,7 +17,7 @@ txt_report = mypy
 ; TODO: Adopt --strict settings, iterating towards something like:
 ; https://github.com/pypa/packaging/blob/master/setup.cfg
 ; Starting with modules that have annotations applied via MonkeyType
-[mypy-twine.auth,twine.cli,twine.package,twine.repository,twine.utils]
+[mypy-twine.auth,twine.cli,twine.exceptions,twine.package,twine.repository,twine.utils,twine.commands]
 ; Enabling this will fail on subclasses of untype imports, e.g. tqdm
 ; disallow_subclassing_any = True
 disallow_any_generics = True
diff --git a/twine/commands/__init__.py b/twine/commands/__init__.py
index 68c05e7b..87e83fcc 100644
--- a/twine/commands/__init__.py
+++ b/twine/commands/__init__.py
@@ -20,7 +20,7 @@
 __all__: List[str] = []
 
 
-def _group_wheel_files_first(files):
+def _group_wheel_files_first(files: List[str]) -> List[str]:
     if not any(fname for fname in files if fname.endswith(".whl")):
         # Return early if there's no wheel files
         return files
@@ -30,7 +30,7 @@ def _group_wheel_files_first(files):
     return files
 
 
-def _find_dists(dists):
+def _find_dists(dists: List[str]) -> List[str]:
     uploads = []
     for filename in dists:
         if os.path.exists(filename):
diff --git a/twine/commands/upload.py b/twine/commands/upload.py
index 57bbce12..a37e8bd0 100644
--- a/twine/commands/upload.py
+++ b/twine/commands/upload.py
@@ -13,6 +13,10 @@
 # limitations under the License.
 import argparse
 import os.path
+from typing import List
+from typing import cast
+
+import requests
 
 from twine import commands
 from twine import exceptions
@@ -21,7 +25,9 @@
 from twine import utils
 
 
-def skip_upload(response, skip_existing, package):
+def skip_upload(
+    response: requests.Response, skip_existing: bool, package: package_file.PackageFile
+) -> bool:
     if not skip_existing:
         return False
 
@@ -44,14 +50,14 @@ def skip_upload(response, skip_existing, package):
     )
 
 
-def upload(upload_settings, dists):
+def upload(upload_settings: settings.Settings, dists: List[str]) -> None:
     dists = commands._find_dists(dists)
 
     # Determine if the user has passed in pre-signed distributions
     signatures = {os.path.basename(d): d for d in dists if d.endswith(".asc")}
     uploads = [i for i in dists if not i.endswith(".asc")]
     upload_settings.check_repository_url()
-    repository_url = upload_settings.repository_config["repository"]
+    repository_url = cast(str, upload_settings.repository_config["repository"])
 
     print(f"Uploading distributions to {repository_url}")
 
@@ -109,7 +115,7 @@ def upload(upload_settings, dists):
     repository.close()
 
 
-def main(args):
+def main(args: List[str]) -> None:
     parser = argparse.ArgumentParser(prog="twine upload")
     settings.Settings.register_argparse_arguments(parser)
     parser.add_argument(
@@ -122,8 +128,8 @@ def main(args):
         "file upload.",
     )
 
-    args = parser.parse_args(args)
-    upload_settings = settings.Settings.from_argparse(args)
+    parsed_args = parser.parse_args(args)
+    upload_settings = settings.Settings.from_argparse(parsed_args)
 
     # Call the upload function with the arguments from the command line
-    return upload(upload_settings, args.dists)
+    return upload(upload_settings, parsed_args.dists)
diff --git a/twine/exceptions.py b/twine/exceptions.py
index cb29dee2..d90c70e3 100644
--- a/twine/exceptions.py
+++ b/twine/exceptions.py
@@ -30,7 +30,7 @@ class RedirectDetected(TwineException):
     """
 
     @classmethod
-    def from_args(cls, repository_url, redirect_url):
+    def from_args(cls, repository_url: str, redirect_url: str) -> "RedirectDetected":
         msg = "\n".join(
             [
                 "{} attempted to redirect to {}.".format(repository_url, redirect_url),
@@ -60,7 +60,9 @@ class UploadToDeprecatedPyPIDetected(TwineException):
     """
 
     @classmethod
-    def from_args(cls, target_url, default_url, test_url):
+    def from_args(
+        cls, target_url: str, default_url: str, test_url: str
+    ) -> "UploadToDeprecatedPyPIDetected":
         """Return an UploadToDeprecatedPyPIDetected instance."""
         return cls(
             "You're trying to upload to the legacy PyPI site '{}'. "
diff --git a/twine/package.py b/twine/package.py
index 9a8ec93e..abfb0c64 100644
--- a/twine/package.py
+++ b/twine/package.py
@@ -78,7 +78,7 @@ def __init__(
         self.blake2_256_digest = hexdigest.blake2
 
     @classmethod
-    def from_filename(cls, filename: str, comment: None) -> "PackageFile":
+    def from_filename(cls, filename: str, comment: Optional[str]) -> "PackageFile":
         # Extract the metadata from the package
         for ext, dtype in DIST_EXTENSIONS.items():
             if filename.endswith(ext):
diff --git a/twine/settings.py b/twine/settings.py
index 76e5cf09..0cb763de 100644
--- a/twine/settings.py
+++ b/twine/settings.py
@@ -44,7 +44,7 @@ def __init__(
         self,
         *,
         sign: bool = False,
-        sign_with: Optional[str] = "gpg",
+        sign_with: str = "gpg",
         identity: Optional[str] = None,
         username: Optional[str] = None,
         password: Optional[str] = None,
@@ -272,7 +272,7 @@ def from_argparse(cls, args: argparse.Namespace) -> "Settings":
         return cls(**settings)
 
     def _handle_package_signing(
-        self, sign: bool, sign_with: Optional[str], identity: Optional[str]
+        self, sign: bool, sign_with: str, identity: Optional[str]
     ) -> None:
         if not sign and identity:
             raise exceptions.InvalidSigningConfiguration(